No graph when 'null value' is not set to connected , while there are no holes in database


  • ubuntu 16.04

  • influxdb:

  • telegraf:

  • grafana: 5.0.0

  • telegraf collect interval is: 2 seconds

  • grafana $__interval is: 2 seconds.

  • Stackin/null value / Null value is set to : null

  • in the ‘group by’ query, fill null is set.

There are no holes in influxdb data, every 2 seconds there is really data.

When changing time interval (in fact, when zooming out time range) , graph finally disappear . It comes back only if i set “null connected”

I don’t want to set to ‘connected’ because it graphes all the time, even if there is a telegraf problem (no collect).

So how to understand that?


Any clues for this problem?